Safe Drinking Water Act

Link to the

Interactive maps

Link to EPA Regulations

Link to the

Status Report of Implementing & Enforcing the UST Program in Indian Country

Groundwater Program Mission Statement

High quality groundwater on the Nez Perce Reservation provides nearly 100% of the potable water supplies for the Nez Perce people. The Lapwai Valley Aquifer is a portion of the federally designated Lewiston Sole Source Aquifer and scientific studies have documented that streams and groundwater are hydrologically connected.  Our mission is to protect high quality groundwater from degradation and to restore contaminated groundwater to beneficial use.

Goals

· Pollution prevention is the most effective method of protecting valuable high quality groundwater resource through implementation of regulatory standards and best management practices to be applied to all activities by the NPT Tribe, industry, agriculture, municipalities, private homeowners, and public transportation corridors within the Clearwater River Watershed

· Science-based soil and groundwater assessments and environmental cleanups will strive to remove contamination where feasible and minimize damages to human health and the environment

· Establishing groundwater monitoring points for both water quality and quantity (e.g. water level) will provide a long term record that will be useful to the Tribe in trend analysis and potentially useful as a predictive tool useful to land managers

FRESHWATER AVAILABLE FOR HUMAN CONSUMPTION

Sole Source Aquifers North Idaho

· Groundwater is the earths largest source of freshwater

· Long term storage makes it vulnerable to over pumping and contamination

Example of Preferential Groundwater Recharge

Hydrogeologic Background

Geologically, the aquifers are contained within stratified basalts of the Columbia River Basalt Group that have been subsequently folded and faulted. Aquifers occur between the basalt flows and are localized primarily along permeable basalt flowtops. The interiors of the flows consist of massive basalt with relatively little water passing

vertically between the basalt flows. This results in a stratification of aquifers that typically function independently of each other. The best example of this vertical separation of aquifers is based on an administrative declaration of a Ground Water

Management Area for the Lindsey Creek Aquifer, which is producing its water from the Saddle Mountain and Wanapum Basalts formation.